Major Histocompatibility Complex Class II DQ Alpha 2 (MHCDQa2)

HLA class II histocompatibility antigen, DQ(6) alpha chain is expressed, but unlike HLA-DQA1, it apparently unable to heterodimerize with HLA class II beta chain paralogues.The low level of HLA-DQA2 expression is apparently due to impaired transcription factor binding to the HLA-DQA2 gene promoter.The alpha chain contains 5 exons. Exon one encodes the leader peptide, exons 2 and 3 encode the two extracellular protein domains, exon 4 encodes the transmembrane domain and the cytoplasmic tail. Within the DQ molecule both the alpha chain and the beta chain contain the polymorphisms specifying the peptide binding specificities, resulting in up to 4 different molecules. Typing for these polymorphisms is routinely done for bone marrow transplantation.